Macromolecules

Question 1

Macromolecules (large, relevant to bio)

Answer 1

1) Carbohydrates
2) Nucleic Acids
3) Proteins
4) Lipids

Polymers: molecule of several monomers (subunit of polymer)

Question 2

Polymer Synthesis & Monomer recovery (opposite rxn)

Answer 2

Polymer: Dehydration synthesis (remove water & form bond)

Monomer: Hydrolysis (add water & break bond)

Question 3

Functional groups (R groups)

Answer 3

1. Hydroxyl group (OH) - alcohols
   1) polar (EN O)
   2) formation H-bonds
   3) dissolution of organic molecules
2. Carbonyl group
   1) ketones (R R) & aldehydes (R H)
   2) polar, forms H-bonds (protein secondary structure)
3. Carboxyl group (aka carboxylic acid)
   Acts as acid (H dissociates cuz of EN O)
4. Amino group (NH2) - aka amine
   Acts as base (picks up H+ ion)
5. Sulfhydryl group (SH or HS) - aka thiol group
   1) Rxn w/ other SH - disulfide bridge (stabilize molecules, proteins)
   2) nonpolar
6. Phosphate group (PO4 2-)
   Negative charge depending on position in molecule (see pic)
7. Methyl group
   1) nonpolar, hydrophobic, nonreactive
   2) affects DNA expression

Question 4

Carbohydrates (sugars, polysaccharides, monomer: monosaccharides-simple sugar)

Answer 4

1) C, H, O (1:2:1) ex: C6H12O6

2) -polysaccharide l: monosaccharides - glycosidic bonds,
- Disaccharide: 2 simple sugars

3) wide range of carbon atoms (6-carbon, 5-carbon, 3-carbon sugars)
4) energy source, structural component of cells

5) Glucose (most important carb)
- energy consumption & storage
- isomer alpha (starch: plants for energy storage, (glycogen in animales) ) - beta (cellulose: cell walls, generally indigestible)

6) chitin (polysach. In fungi & arthropods)
- cross-linked polymer of N-acetylglucosamine

Question 5

Isomers

Answer 5

Structural isomers (structure changes, chemical formula same)

Stereo isomers (mirror images of each other)

Question 6

Nucleic acids (info necessary for function of cell & heredity - DNA & RNA)

Answer 6

Polymer: Nucleic acid
Monomer: nucleotides (phosphate group, pentose sugar, nitrogenous base)
-nucleotides joined w/ phosphodiester bonds (b/w sugars & phosphate groups) -free OH end (3’ end), free phosphate group (5’ end)

5 Nitrogenous bases:
Purines (2 rings): Adenine & Guanine
Pyrimidines (1 ring): Cytosine, Thymine (DNA) & Uracil (RNA)

DNA: info for heredity & functioning of cell, (sugar: deoxyribose)

1) info coded by base sequence in molecules
2) 2 chains: H-bonds, complementary base paring, double helix shape

RNA: single strand nucleic acid (sugar: ribose)

1) mRNA: transfer info from DNA to rest of cell
2) rRNA: part of ribosome
3) tRNA: carries amino acids to ribosome

Ex nucleotide: ATP (energy metabolism & energy currency of cell)
-Hydrolysis: release of energy (used in cellular processes)

Question 7

Proteins (polymer, monomer: amino acids, peptide bonds)

Answer 7

7 functions:

1) Support: structural role in cells (elastin maintins tissue structure)
2) Storage: Ca & ion storage in small storage proteins (milk protein casein stores Ca)
3) Motion: Move materials within cell (actin & myosin proteins - contraction of muscle fibres) (flagellin by bacteria for motion)
4) Transport: transport small molecules around body, channel through membranes (passage of nutrients, molecules) (lac permease)
5) Regulation: Hormones regulate gene expression, cells respond to change in environ. (Insulin regulates absorption of blood glucose)
6) Enzyme Catalysis: facilitate chem rxn (Luciferase by fireflies - bioluminescence)
7) Defence: shape - recognize & bind to foreign organisms (protect body against invaders) (immunoglobulins, venoms)

Question 8

Lipids (diverse group, water insoluble (hydrophobic), non-polar C-H bonds)

Answer 8

Fats (triglycerides, vary in length & character)
-glycerol molecule + 3 fatty acid chains

Fatty acids:
Saturated: (no double bonds)
Unsaturated: (double bonds)
-mono-unsaturated: 1 double bond
-poly-unsaturated: multiple double bonds 

Double bond: low m.p. (Prevents full packing of lipids)

Class of lipid: Steroid (cell growth & structure)

• Testosterone (cell growth)
• Cholesterol (cell structure)

Phospholipids: Amphipathic molecules (hydrophilic head - glycerol + hydrophobic tail - fatty acids)
-Form bilayers (micelles) in aq environ.